This writer initially looking depressed becomes cheery (6)
I believe the answer is:
mellow
'cheery' is the definition.
(thesaurus)
'this writer initially looking depressed' is the wordplay.
'this writer' becomes 'me' (the person who is writing these clues).
'initially' says to take the initial letters.
'depressed' becomes 'low' (synonyms).
The first letter of 'looking' is 'l'.
'me'+'l'+'low'='MELLOW'
'becomes' acts as a link.
(Other definitions for mellow that I've seen before include "Pleasantly smooth/soft" , "Grown gentle or mild" , "Calm and relaxed" , "under the influence of drink" , "Aged to full flavour" .)